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    <script>
        a = 10;
        let c = 'abc"abc"';
        let b = "abc'abc'";

        console.log(typeof(a));
    </script>   

    <!-- <script>
        let arr = [1,2,3,4];
        arr['index'] = 10;
        console.log(arr);


        let ret = {
            a:10,
            b :'wen',
        }
        ret['c'] = 20;
        console.log(ret['c']);
    </script> -->
       

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